Rabbi Elyashiv has been in the hospital since February, when he suffered from pneumonia and other maladies. On Tuesday morning, a "virulent infection" was found in his blood.

The family members of Rabbi Elyashiv have been called to his bedside and they have asked the public to pray for his health (Yosef Shalom Ben Chaya Mousha).

Shlomo Kook, the spokesman for the family of Rabbi Elyashiv, told IDF Radio: "The Rabbi's situation is critical. The entire nation has been moving between despair and hope. People got up and started to pray in the middle of the night in many places across the world."

Rabbi Elyashiv is often referred to as the Posek HaDor, the leading authority on halakha in this generation.